title: Using sequence data to infer the antigenicity of influenza virus.
abstract: The efficacy of current influenza vaccines requires a close antigenic match between circulating and vaccine strains. As such, timely identification of emerging influenza virus antigenic variants is central to the success of influenza vaccination programs. Empirical methods to determine influenza virus antigenic properties are time-consuming and mid-throughput and require live viruses. Here, we present a novel, experimentally validated, computational method for determining influenza virus antigenicity on the basis of hemagglutinin (HA) sequence. This method integrates a bootstrapped ridge regression with antigenic mapping to quantify antigenic distances by using influenza HA1 sequences. Our method was applied to H3N2 seasonal influenza viruses and identified the 13 previously recognized H3N2 antigenic clusters and the antigenic drift event of 2009 that led to a change of the H3N2 vaccine strain.
  
  
  OBJECTIVE
  This report supplies a novel method for quantifying antigenic distance and identifying antigenic variants using sequences alone. This method will be useful in influenza vaccine strain selection by significantly reducing the human labor efforts for serological characterization and will increase the likelihood of correct influenza vaccine candidate selection.
authors.affiliation: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA.
authors.forename: Hailiang
authors.initials: H
authors.lastname: Sun
authors.forename: Jialiang
authors.initials: J
authors.lastname: Yang
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Long
authors.forename: Kun
authors.initials: K
authors.lastname: Jia
authors.forename: Guohua
authors.initials: G
authors.lastname: Yang
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Webby
authors.forename: Xiu-Feng
authors.initials: XF
authors.lastname: Wan
mesh_terms: D000956:Antigens, Viral / Q000235:genetics* / Q000276:immunology*; D019295:Computational Biology / Q000379:methods*; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics* / Q000276:immunology*; D007251:Influenza, Human / Q000821:virology*
chemical_list: D000956:Antigens, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus